Re: What is a Modern RPG Programmer???

I prefer to stick with sub-procedures, even if they have no parameters or
return value simply because it is not always easy to just convert a single
subroutine to a sub-procedure if you need to. It isn't always easy because
subroutines often call other subroutines, but you can't just execute a
subroutine that exists outside the sub-procedure. So once you change begsr
to dcl-proc, you have to go and convert all the subroutines that are called
by the initial subroutine. Sometimes I find it is easier, for code reuse,
just to use a subroutine in existing code. But in new programs, I do not
code subroutines at all because they are much more limited.

On Mon, Feb 5, 2018 at 12:09 PM, Richard Schoen <
Richard.Schoen@xxxxxxxxxxxxxxx> wrote:

I was thinking on this one a bit and aren't sub-procedures main functions
where you pass parms in and get info back.

Much like in other programming I do, I like to think of them as a black
box, especially when used across applications.

If a sub-procedure for some reason uses all the global program variables
and is simply being used to encapsulate some looping logic or something
similar, why not use a subroutine instead ?

Just thinking out loud on this.

I don't do a ton of RPG coding any more so a few example use-cases would
be good to hear about.

Regards,
Richard Schoen
Director of Document Management
e. richard.schoen@xxxxxxxxxxxxxxx
p. 952.486.6802
w. helpsystems.com

----------------------------------------------------------------------

message: 1
date: Mon, 5 Feb 2018 11:23:02 -0500
from: Jon Paris <jon.paris@xxxxxxxxxxxxxx>
subject: Re: What is a Modern RPG Programmer???

I have to agree with Rob on this.

My policy is that if you want to use a subprocedure go ahead. If you want
to use a subroutine then you need to explain to me what benefits it offers
and why you are convinced that it will never need parameters or a return
value.

Future protection - I don't want my programmers producing future relics.


Jon Paris

www.partner400.com
www.SystemiDeveloper.com

On Feb 5, 2018, at 10:57 AM, Rob Berendt <rob@xxxxxxxxx> wrote:

John Erps,

I didn't say never use a subroutine. I said that I personally went
hardcore on only using subprocedures for a year. And stated my reason.
You can see that below in the thread. Once I broke the habit of
falling back to what was easy and comfortable I used subroutines where
appropriate. I really thought I was quite clear on that.

One thing to keep in mind is to always think of the future.
What may be a subroutine in an existing program could evolve.
- First into a subprocedure
- Next moved out of the main program into a service program.
- Then someone could create a UDF from that service program
subprocedure
- That UDF could be called by SQL with stuff like Select item_number,
onhand(item_number)...
- That UDF could be imbedded into an SQL view Create view Item_user
as (select item_number, onhand(item_number)...
and thus making user queries easier.


Rob Berendt
--
IBM Certified System Administrator - IBM i 6.1 Group Dekko Dept 1600
Mail to: 2505 Dekko Drive
Garrett, IN 46738
Ship to: Dock 108
6928N 400E
Kendallville, IN 46755
http://www.dekko.com

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